1. Field of the Invention
The present invention relates to novel methylated prostaglandin derivatives which reduce extraordinarily side-effect maintaining superior physiological activity and preparation thereof and usages thereof.
2. Description of the Prior Arts
As it is well known, prostaglandins are found in human-body and are important physiological active compounds which impart hypotonia effect, gastric juice secretion inhibiting effect, bronchiectatic effect, blood platelet aggregation inhibiting effect or promoting effect.
Prostaglandins are abbreviated as PGs hereinafter. PGE and PGF are well known to have some special physiological activities such as hystrotrimus and yellow body degeneration, and they are useful for parturifacient, abortion at initial or middle stages of pregnancy and placental abruption after partus and control of menstrual disorder. (Brit. Med. J., 4, 618(1978), Brit. Med. J., 4 621 (1968), Amr. N.Y. Acad. Sci., 180, 456(1970); Pharmacia Vol. 9, No. 6 P. 399-402 (1973)). It is also possible to expect control of sexual cycle of female mammals, abortion and contraception.
However, the useful methylated prostaglandins cause, in its administration as a medicine, nausea, vomitting and diarrhea and also sudden variations of blood pressure, pulse and respiration. In spite of the fact that prostaglandins have been expected as useful medicines, they have been limited to only for special therapy because of serious side-effect.
The inventors have studied to develop novel methylated prostaglandin derivatives having extraordinarily reduced its side-effect.